mcgiehan



(No Model.)

P. H. MGGIEHAN.

HOLLOW MAST.

Patented Apr. 27, 1897.'

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UNTTED STATES PATENT OFFICE.

PATRICK II. MGGIEHAN, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO JOI-IN H. HIGGINS, OF SAME PLACE.

HOLLOW MAST.

SPECIFICATION forming part of Letters Patent NO. 581,514, dated April 27, 1897.

Application filed April 25, 1896. Serial No. 589,029. (No model.)

To LZZ whom t may concern:

Beit known that I, PATRICK H. MCGIEHAN, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Masts and Similar Structures, of which the following is a specification.

My invention relates especially to that class of masts Which are hollowed throughout the length thereof with a view to diminish the Weight as also the size and resistance of the structure to air-currents; and the general object of my invention is to obtain a simple and effective means for uniting a series of longitudinally-divided parts or sections constituting the body of the mast. This object I have accomplished by the novel features of construction hereinafter described, and illustrated in the accompanying drawings, in Which- Figure I represents a longitudinal central section of a mast or spar embodying the invention. Fig. II represents a like section of the mast on a larger scale than in the preceding ligure and omitting the supporting-plates. Fig. III represents a cross-section of the body or shell of the mast. Fig. IV represents a longitudinal central section thereof with a fastening for the supporting-plates. Fig. V represents a plan View of one of the supporting-plates in blank form. Fig. VI represents a horizontal section of one of the supportingrings. Fig. VII represents a plan View of one of the anchor-plates. Fig. VIII represents a plan view of the other of the anchorplates. Fig. IX represents a side view of one of the truss-bars.

Similarletters of reference indicate similar parts.

The body of the mast is divided longitudinally into a series of parts o'r sections A-in this example three in number-which are of suitable shape and united to produce a hollowed article, as shown. At or near each end of the mast the united sections A are formed with a shoulder B, to afford a support for an anchor-plate C, and exterior of said shoulder with a recess D for permitting access to the heads and nuts of truss rods or bolts e, to be 5o next described.

The truss-bolts e extend through proper holes in the anchor-plates C, with their heads and nuts impinging against the outer surface of said plates, respectively, said bolts t-hus extending approximately the length of the mast, and at suitable points throughout the interior of the mast are disposed supportingplates f, which also are perforated for the passage of the truss-bolts therethrough.- 6o These supporting-plates f are secured in the desired positions by means of screws or bolts which are inserted through a iiange f on either of the said plates from an inward direction into the mast, these supporting-plates with their flanges conforming to the interior diameter of the structure. The effect of the supporting-plates fis to brace and support not only the body of the mast, but also the truss-bolts-namely, by retaining said bolts 7o in symmetrical relation to each other, thus insuring uniformity of strain.

In the construction of the mast I introduce the supporting-plates f, as also the anchorplates C and truss-bolts e therein, before the mast-sections A are united to each other, and after the sections have been united I t into that end of the mast adjacent to which are situated the screw-nuts of the truss-bolts a plug g, which is removable, and thus affords 8o access to the nuts for tightening up the bolts.

I also provide the mast, at or near each end thereof, with an external clamping-ring s, to assist in holding the mast-sections together, these clamping-rings being usually in sections and bolted or riveted together.

In the formation of the supporting-plates f I usually employ a blank of the general form shown in Fig. V, the same having peripheral notches f", and being in practice bent or 9o turned up approximately along the dotted ,line indicated in said ligure to form the iange f', whereby either of said plates is secured to and within the mast, as before stated.

It may be remarked that my invention is applicable to any spar for a yacht or sailing-- vessel, meaning a mast, boom, galt', topmast, tbc., and also to a boom for a dredging-machine, also known as a mud-digger, and to flag-poles, telegraph-poles, and other similar structures. It may also be remarked that the structure may be either round or of any other desirable cross-section.

That I claim as my invention, and desire to secure by Letters Patent, is-

l. In a hollowr inast or similar structure divided longitudinally in to sections, the Coinbnation with anchor-plates, C, of truss-bolts, e, engaging with said plates at their opposite ends and extending approximately the length of the mast, Within the same, substantially as and for the purpose herein described.

2. In a hollow mast or similar structure divided longitudinally into sections, the Conibination of anchor-plates, C, at or near the 

